Luminaire

Abstract

To provide technology which makes it hard for heat to transmit to a translucent member.SOLUTION: A luminaire includes: a housing which has an opening at an upper end, and which is long in one direction; a substrate; a plurality of light emitting devices; and a translucent member. The substrate is positioned on the inner bottom surface of the housing, and extends along the longer direction of the housing. The plurality of light emitting devices is mounted on the upper surface of the substrate, and is arranged along the longer direction. The translucent member is positioned on the upper side of the plurality of light emitting devices, and mounted on a pair of first side wall part and a second side wall part along the longer direction of the housing. The housing includes: a first groove provided on the inner wall surface of the first side wall part, positioned further downward than the translucent member, and extending along the longer direction; and a plurality of heat radiation grooves provided on the outer bottom surface of the housing, and extending along the longer direction. The plurality of heat radiation grooves includes a first heat radiation groove and a second heat radiation groove deeper than the first heat radiation groove.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present disclosure relates to a lighting device.

Background Art

[0002] Patent Document 1 describes a technique related to a lighting device.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] There is room for improvement in the lighting device.

Means for Solving the Problems

[0005] A lighting device is disclosed. In one embodiment, the lighting device includes a housing having an opening at an upper end and being long in one direction, a substrate, a plurality of light-emitting devices, and a light-transmissive member. The substrate is located on the inner bottom surface of the housing and extends along the longitudinal direction of the housing. The plurality of light-emitting devices are mounted on the upper surface of the substrate and are arranged along the longitudinal direction. The light-transmissive member is located above the plurality of light-emitting devices and is attached to a pair of first side wall portions and second side wall portions along the longitudinal direction of the housing. The housing has a first groove provided on the inner wall surface of the first side wall portion and located below the light-transmissive member and extending along the longitudinal direction, and a plurality of heat dissipation grooves provided on the outer bottom surface of the housing and extending along the longitudinal direction. The plurality of heat dissipation grooves include a first heat dissipation groove and a second heat dissipation groove deeper than the first heat dissipation groove.

Effects of the Invention

[0006] Heat is less likely to be transmitted to the light-transmissive member.

Brief Description of the Drawings

[0007]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Embodiments for Carrying Out the Invention

[0008] Figs. 1 to 3 are schematic diagrams showing an example of the lighting device 1. Fig. 4 is a schematic exploded perspective view showing an example of the lighting device 1. Fig. 1 shows an example of how the lighting device 1 is seen from above. Fig. 2 shows an example of how the lighting device 1 is seen from below. Fig. 3 shows an example of how the lighting device 1 is seen from the side. Fig. 5 is a schematic diagram showing an example of the cross-sectional structure taken along the arrow A-A in Fig. 1. In Fig. 4, the shape of the housing 2 is shown in a simplified manner as compared with Fig. 5.

[0009] The lighting device 1 can emit light to the outside. The lighting device 1 may be used indoors or outdoors. In the former case, the lighting device 1 may be arranged on the ceiling indoors or on the wall indoors. The light emitted by the lighting device 1 may not only simply illuminate the space but also be irradiated onto the plant for growing the plant. The plant irradiated with the light emitted by the lighting device 1 may be a vegetable. The vegetable irradiated with the light emitted by the lighting device 1 may be a leafy vegetable such as lettuce.

[0010] As shown in FIGS. 1 to 5, the lighting device 1 extends in one direction, for example, and has an elongated shape. The lighting device 1 includes a substrate 3 and a housing 2 that houses a plurality of light-emitting devices 4. The lighting device 1 emits the light emitted by the plurality of light-emitting devices 4 in the housing 2 to the outside of the housing 2.

[0011] The housing 2 extends in one direction, for example, and has an elongated shape. The longitudinal direction of the housing 2 coincides with the longitudinal direction of the lighting device 1. The housing 2 forms, for example, an elongated rectangular parallelepiped with an upper surface and both side surfaces in the longitudinal direction being open. As shown in FIG. 4 and the like, the housing 2 has, for example, an opening 20 at the upper end and openings 21 at both ends in the longitudinal direction.

[0012] The housing 2 includes, for example, a bottom wall portion 25 extending along the longitudinal direction and a pair of side wall portions 26 extending along the longitudinal direction. The pair of side wall portions 26 are erected at both ends in the short side direction of the bottom wall portion 25 (that is, the direction perpendicular to the longitudinal direction and the thickness direction of the bottom wall portion 25). One of the pair of side wall portions 26 (for example, the right side wall portion) may be the first side wall portion, and the other side wall portion (for example, the left side wall portion) may be the second side wall portion.

[0013] Hereinafter, one side in the longitudinal direction of the lighting device 1 is referred to as the front side of the lighting device 1, and the other side in the longitudinal direction of the lighting device 1 is referred to as the rear side of the lighting device 1. The front-rear direction of the lighting device 1 coincides with the longitudinal direction of the lighting device 1. Further, the direction perpendicular to the longitudinal direction of the lighting device 1 (in other words, the longitudinal direction of the housing 2) and the height direction of the side wall portion 26 (that is, the vertical direction) is referred to as the width direction of the lighting device 1. Also, the left side in FIG. 5 is defined as the left side of the lighting device 1, and the right side in FIG. 5 is defined as the right side of the lighting device 1, and the lighting device 1 will be described.

[0014] The lighting device 1 includes a pair of lid portions 6 that close the openings 21 at both ends in the longitudinal direction (in other words, the front-rear direction) of the housing 2. The pair of lid portions 6 are fixed to the housing 2 so as to close the openings 21 at both ends in the longitudinal direction of the housing 2. The pair of lid portions 6 may be, for example, screwed to the housing 2. The front lid portion 6 is fixed to the housing 2 so as to cover the outer surface of the front end portion of the housing 2 (in other words, one end portion in the longitudinal direction of the housing 2). The rear lid portion 6 is fixed to the housing 2 so as to cover the outer surface of the rear end portion of the housing 2 (in other words, the other end portion in the longitudinal direction of the housing 2). The lid portion 6 may be fixed to the housing 2 by passing two screws through two through holes of the lid portion 6 from the outside and screwing them into the housing 2 respectively.

[0015] The substrate 3 is located on the inner bottom surface 120 of the housing 2 and extends along the longitudinal direction. The inner bottom surface 120 of the housing 2 can also be said to be the inner wall surface (in other words, the upper surface) of the bottom wall portion 25 of the housing 2. A plurality of light-emitting devices 4 are mounted on the upper surface 35 of the substrate 3. The light-emitting device 4 is arranged, for example, at the central portion in the width direction of the upper surface 35 of the substrate 3. A conductive pattern is formed on the upper surface 35 of the substrate 3, and the conductive pattern is electrically connected to each light-emitting device 4. The substrate 3 is also called a wiring substrate. The substrate 3 may be, for example, a rigid substrate, a flexible substrate, or a rigid-flexible substrate, etc.

[0016] The plurality of light-emitting devices 4 mounted on the upper surface 35 of the substrate 3 are arranged side by side along the longitudinal direction. Each light-emitting device 4 emits light upward. The lighting device 1 emits the light emitted by the plurality of light-emitting devices 4 to the outside of the housing 2 from the opening 20 at the upper end of the housing 2.

[0017] The substrate 3 may be, for example, screwed to the housing 2. The substrate 3 is fixed to the bottom wall portion 25 of the housing 2 by, for example, a plurality of screws 13. The substrate 3 may be provided with a plurality of through holes 30 through which a plurality of screws respectively pass.

[0018] FIG. 6 is a schematic perspective view showing an example of the light-emitting device 4. FIG. 7 is a schematic view showing an example of the cross-sectional structure of the light-emitting device 4 in the cross-section indicated by the two-dot chain line in FIG. 6. As shown in FIGS. 6 and 7, the light-emitting device 4 includes, for example, an element mounting substrate 40, a light-emitting element 41, a frame body 42, a sealing member 43, and a wavelength conversion member 44.

[0019] The element mounting substrate 40 includes, for example, an insulating base material. The material of the base material may be, for example, a ceramic such as alumina or mullite, or a glass ceramic. The light-emitting element 41 is mounted on the upper surface of the element mounting substrate 40. For example, conductive patterns are formed on the upper surface, inner layer, and lower surface of the element mounting substrate 40. The light-emitting element 41 is electrically connected to the conductive pattern formed on the upper surface of the element mounting substrate 40. The light-emitting element 41 is electrically connected to the substrate 3 by electrically connecting the conductive pattern on the lower surface of the element mounting substrate 40 to the conductive pattern on the upper surface 35 of the substrate 3 with solder or the like.

[0020] Power is supplied to the substrate 3 from the outside of the lighting device 1 through an electric wire. The electric wire is electrically connected to the substrate 3 and is drawn out from one of the lid portions 6 to the outside. The power supplied to the substrate 3 is supplied to the light-emitting element 41 through the element mounting substrate 40. The light-emitting element 41 emits light based on the supplied power.

[0021] The light-emitting element 41 is, for example, a semiconductor light-emitting element. The light-emitting element 41 may be a light-emitting diode (LED). The light-emitting element 41 emits light upward. The light-emitting element 41 emits light in a wavelength range of, for example, about 370 nm to 440 nm.

[0022] The frame body 42 surrounds, for example, the light-emitting element 41 on the element mounting substrate 40. The frame body 42 may be made of, for example, resin. The resin constituting the frame body 42 may be mixed with powder of a porous or metal oxide ceramic material. Further, a metal layer and a metal plating layer covering the metal layer may be laminated on the inner wall surface of the frame body 42. The material of the metal layer may be, for example, tungsten, molybdenum, copper, silver, or the like. Also, the material of the plating layer may be, for example, nickel or gold. Such a plating layer can reflect the light emitted by the light-emitting element 41.

[0023] The sealing member 43 seals the inside of the frame body 42. The sealing member 43 has translucency. The material of the sealing member 43 may be, for example, a resin having translucency and insulation properties such as silicone resin, acrylic resin, or epoxy resin.

[0024] The wavelength conversion member 44 is attached to the upper end portion of the frame body 42 so as to close the opening at the upper end of the frame body 42, for example. The wavelength conversion member 44 can convert the wavelength of the light emitted by the light-emitting element 41. The wavelength conversion member 44 has, for example, a base material and a large number of phosphors 45 contained in the base material. The base material may be made of, for example, a resin or glass having translucency and insulation properties. The resin constituting the base material may be a resin having translucency such as fluororesin, silicone resin, acrylic resin, or epoxy resin. The phosphor 45 can be excited by the light emitted by the light-emitting element 41 and emit light. The light-emitting device 4 can emit, for example, the light emitted by the light-emitting element 41 and the light emitted by the large number of phosphors 45 of the wavelength conversion member 44 toward the opening 20 at the upper end of the housing 2. By appropriately setting the type of the phosphor 45, the spectrum of the light emitted by the light-emitting device 4 can be changed. The large number of phosphors 45 may include a red phosphor, a green phosphor, a blue phosphor, or a yellow phosphor.

[0025] As shown in FIG. 5, the lighting device 1 includes a light-transmitting member 5 that is located above a plurality of light-emitting devices 4 and is attached to a pair of side wall portions 26 of the housing 2. The light-transmitting member 5 can transmit the light emitted by the light-emitting device 4. The material of the light-transmitting member 5 may be, for example, an acrylic resin or glass. The housing 2 can hold the light-transmitting member 5. The light-transmitting member 5 is, for example, plate-shaped and extends along the longitudinal direction. The light-transmitting member 5 is held, for example, by the inner wall surfaces 260 of the pair of side wall portions 26. When the light-transmitting member 5 is viewed from the lower surface side, the light-transmitting member 5 closes the upper opening 20 of the housing 2. The light emitted by the light-emitting device 4 passes through the light-transmitting member 5 and is emitted outside the housing 2 from the upper opening 20 of the housing 2.

[0026] Each of the pair of side wall portions 26 has an upper locking portion 261 and a lower locking portion 262 that sandwich the light-transmitting member 5 in the vertical direction. The upper locking portion 261 and the lower locking portion 262 are provided on the inner wall surface 260 of the side wall portion 26 and protrude inside the housing 2. The upper locking portion 261 and the lower locking portion 262 can also be said to be protruding portions that protrude inside the housing 2.

[0027] The upper locking portion 261 is provided at the upper end portion of the inner wall surface 260 of the side wall portion 26. The upper locking portion 261 and the lower locking portion 262 extend along the longitudinal direction. The upper locking portion 261 and the lower locking portion 262 extend from one end to the other end in the longitudinal direction of the housing 2. The upper locking portion 261 and the lower locking portion 262 hold the end portions in the width direction (the left and right end portions in FIG. 5) of the plate-shaped light-transmitting member 5 by sandwiching them in the vertical direction. The end portions in the width direction of the light-transmitting member 5 are locked in the groove 263 between the upper locking portion 261 and the lower locking portion 262. It can also be said that the groove 263 is provided on the inner wall surface 260 of the side wall portion 26. The groove 263 extends from the front side to the rear side of the housing 2 along the longitudinal direction. The front opening of the groove 263 constitutes a part of the front opening 21 of the housing 2. The rear opening of the groove 263 constitutes a part of the rear opening 21 of the housing 2.

[0028] The light-transmissive member 5 is inserted, for example, from the opening 21 at one end in the longitudinal direction of the housing 2 into the grooves 263 inside the pair of side wall portions 26, and then slid in the longitudinal direction (in other words, the front-rear direction) to be attached to a predetermined position of the housing 2. Thereafter, the pair of lid portions 6 are attached to both ends in the longitudinal direction of the housing 2 so as to close the openings 21 at both ends in the longitudinal direction (in other words, the front-rear direction) of the housing 2, respectively.

[0029] In the left side wall portion 26, the tip of the upper locking portion 261 protruding inward is located closer to the outer wall surface 269 side of the left side wall portion 26 than the tip of the lower locking portion 262 protruding inward. Similarly, in the right side wall portion 26, the tip of the upper locking portion 261 is located closer to the outer wall surface 269 side of the right side wall portion 26 than the tip of the lower locking portion 262. In this example, it can also be said that the amount of protrusion of the upper locking portion 261 inward of the housing 2 is smaller than the amount of protrusion of the lower locking portion 262 inward of the housing 2.

[0030] Thus, since the tip of the upper locking portion 261 is located closer to the outer wall surface 269 side of the side wall portion 26 than the tip of the lower locking portion 262, the orientation angle α (see FIG. 5) of the light emitted from the opening 20 at the upper end of the housing 2 can be increased. Also, as in the example of FIG. 5, when the tip of the upper locking portion 261 is located closer to the outer wall surface 269 side of the side wall portion 26 than the tip of the lower locking portion 262 in each of the pair of side wall portions 26, the orientation angle α of the light emitted from the opening 20 at the upper end of the housing 2 can be further increased.

[0031] Note that in one of the pair of side wall portions 26, the tip of the upper locking portion 261 does not necessarily have to be located closer to the outer wall surface 269 side of the side wall portion 26 than the tip of the lower locking portion 262. For example, the tip of the lower locking portion 262 may be located closer to the outer wall surface 269 side of the side wall portion 26 than the tip of the upper locking portion 261, or the position of the tip of the upper locking portion 261 in the width direction may be the same as the position of the tip of the lower locking portion 262 in the width direction. Also, in each of the pair of side wall portions 26, the tip of the upper locking portion 261 does not necessarily have to be located closer to the outer wall surface 269 side of the side wall portion 26 than the tip of the lower locking portion 262.

[0032] The housing 2 has a heat dissipation function of dissipating the heat generated by the light emitting device 4 to the outside of the housing 2. The housing 2 is made of, for example, a material with good thermal conductivity. The material of the housing 2 may be a metal such as aluminum, copper or stainless steel, or may be plastic or resin. The heat generated by the plurality of light emitting devices 4 is dissipated from the housing 2 to the outside of the housing 2.

[0033] As shown in FIGS. 2 and 5, a plurality of heat dissipation grooves 200 extending along the longitudinal direction are provided on the outer bottom surface 125 of the housing 2. Thereby, the heat dissipation effect of the housing 2 can be enhanced. The plurality of heat dissipation grooves 200 are arranged along the width direction (the left-right direction in FIG. 5). Each heat dissipation groove 200 is provided on the outer bottom surface 125 of the housing 2 while avoiding the region covered by the lid portion 6. The outer bottom surface 125 of the housing 2 can also be said to be the lower surface of the housing 2. Note that the housing 2 may not include the plurality of heat dissipation grooves 200.

[0034] The plurality of heat dissipation grooves 200 include a heat dissipation groove 201 and a heat dissipation groove 202 deeper than the heat dissipation groove 201. The heat dissipation groove 201 may be the first heat dissipation groove 201, and the heat dissipation groove 202 may be the second heat dissipation groove 202. The heat dissipation groove 202 may include a second heat dissipation groove 202 and a third heat dissipation groove 202. In this example, the plurality of heat dissipation grooves 200 include a plurality of heat dissipation grooves 201 and a plurality of heat dissipation grooves 202. The plurality of heat dissipation grooves 200 include, for example, five heat dissipation grooves 201 and two heat dissipation grooves 202. The protrusions on both sides of the heat dissipation groove 200 that define the heat dissipation groove 200 can also be said to be heat dissipation ribs 210. It can also be said that the outer bottom surface 125 of the housing 2 has a plurality of heat dissipation ribs 210 extending along the longitudinal direction. The plurality of heat dissipation ribs 210 are arranged along the width direction.

[0035] The depths of the plurality of heat dissipation grooves 201 are, for example, the same as each other. The plurality of heat dissipation grooves 201 includes a heat dissipation groove 201a having a portion overlapping with the plurality of light emitting devices 4 in the vertical direction. The heat dissipation groove 201a is, for example, located directly below the plurality of light emitting devices 4. Thereby, the heat generated from the light emitting device 4 can be efficiently dissipated. The heat dissipation groove 201a is provided, for example, at the central portion in the width direction of the outer bottom surface 125 of the housing 2. For example, the center in the width direction of the heat dissipation groove 201a coincides with the center in the width direction of each light emitting device 4. Also, for example, the size in the width direction of the heat dissipation groove 201a is smaller than the size in the width direction of each light emitting device 4. For example, the left end of the heat dissipation groove 201a is located on the right side of the left end of the light emitting device 4, and the right end of the heat dissipation groove 201a is located on the left side of the right end of the light emitting device 4.

[0036] Note that the heat dissipation groove 201a only needs to have a portion overlapping with each light emitting device 4 in the vertical direction. For example, the center in the width direction of the heat dissipation groove 201a does not necessarily coincide with the center in the width direction of each light emitting device 4. Also, for example, the size in the width direction of the heat dissipation groove 201a may be the same as the size in the width direction of each light emitting device 4, or may be larger than the size in the width direction of each light emitting device 4. Also, the left end of the heat dissipation groove 201a may be located on the left side of the left end of the light emitting device 4. Also, the right end of the heat dissipation groove 201a may be located on the right side of the right end of the light emitting device 4. Also, when the size in the width direction of the light emitting device 4 is large, a plurality of heat dissipation grooves 201a may be provided on the outer bottom surface 125 of the housing 2.

[0037] The plurality of heat dissipation grooves 201 includes two heat dissipation grooves 201b having portions overlapping with the vicinity of both ends in the width direction of the substrate 3 in the vertical direction. The two heat dissipation grooves 201b are, for example, respectively located directly below both ends in the width direction of the substrate 3. For example, the left end of the left heat dissipation groove 201b is located on the right side of the left end of the substrate 3, and the right end of the right heat dissipation groove 201b is located on the left side of the right end of the substrate 3. The widths (in other words, the sizes in the width direction) of the two heat dissipation grooves 201b are, for example, the same as each other. Also, the width of each heat dissipation groove 201b is, for example, the same as the width of the heat dissipation groove 201a.

[0038] Note that the left heat dissipation groove 201b only needs to have a portion overlapping with the left end portion of the substrate 3 in the vertical direction. For example, the left end of the left heat dissipation groove 201b may be located to the left of the left end of the substrate 3. Also, the right heat dissipation groove 201b only needs to have a portion overlapping with the right end portion of the substrate 3 in the vertical direction. For example, the right end of the right heat dissipation groove 201b may be located to the right of the right end of the substrate 3. Also, the widths of the two heat dissipation grooves 201b may be different from each other. Also, the width of at least one of the two heat dissipation grooves 201b does not have to be the same as the width of the heat dissipation groove 201a.

[0039] The plurality of heat dissipation grooves 201 include two heat dissipation grooves 201c respectively located between the left heat dissipation groove 201b and the central heat dissipation groove 201a, and between the right heat dissipation groove 201b and the central heat dissipation groove 201a. The widths of the two heat dissipation grooves 201c are, for example, the same as each other. Also, the width of each heat dissipation groove 201c is, for example, larger than the widths of the heat dissipation groove 201a and the heat dissipation groove 201b.

[0040] Note that the widths of the two heat dissipation grooves 201c may be different from each other. Also, the width of at least one of the two heat dissipation grooves 201c may be the same as the width of at least one of the heat dissipation groove 201a and the heat dissipation groove 201b, or may be smaller than the width of at least one of the heat dissipation groove 201a and the heat dissipation groove 201b.

[0041] In the above example, the number of heat dissipation grooves 201 with a relatively small depth was five, but the number of heat dissipation grooves 201 is not limited to this. The number of heat dissipation grooves 201 may be one, or may be six or more.

[0042] The depths of the two heat dissipation grooves 202 with relatively large depths are, for example, the same as each other. The upper ends of each heat dissipation groove 202 are located above the upper ends of each heat dissipation groove 201. Each of the two heat dissipation grooves 202 is located, for example, outside the substrate 3 in the width direction. In the width direction, the right end of the left heat dissipation groove 202 is located outside the left end of the substrate 3. In the width direction, the left end of the right heat dissipation groove 202 is located outside the right end of the substrate 3. Here, the left heat dissipation groove 202 may be the second heat dissipation groove 202, and the right heat dissipation groove 202 may be the third heat dissipation groove 202.

[0043] The left heat dissipation groove 202 is located, for example, on the outer wall surface 269 side of the left side wall portion 26 rather than the substrate 3. The right heat dissipation groove 202 is located, for example, on the outer wall surface 269 side of the right side wall portion 26 rather than the substrate 3. In the width direction, the end of the left heat dissipation groove 202 on the substrate 3 side is located on the outer wall surface 269 side of the left side wall portion 26 rather than the end of the substrate 3 on the left side wall portion 26 side. In the width direction, the end of the right heat dissipation groove 202 on the substrate 3 side is located on the outer wall surface 269 side of the right side wall portion 26 rather than the end of the substrate 3 on the right side wall portion 26 side.

[0044] The widths of the two heat dissipation grooves 202 are, for example, the same as each other. Also, the width of each heat dissipation groove 202 is, for example, the same as the widths of the heat dissipation grooves 201a and 201b.

[0045] Note that at least one of the two heat dissipation grooves 202 may have a portion overlapping the substrate 3 in the vertical direction. For example, the right end of the left heat dissipation groove 202 may be located on the right side of the left end of the substrate 3, and the left end of the left heat dissipation groove 202 may be located on the left side of the left end of the substrate 3. Also, at least one of the two heat dissipation grooves 202 does not have to be located outside the substrate 3, similar to the heat dissipation groove 201. Also, the widths of the two heat dissipation grooves 202 may be different from each other. Also, the width of at least one of the two heat dissipation grooves 202 does not have to be the same as the width of at least one of the heat dissipation grooves 201a and 201b. Also, the width of at least one of the two heat dissipation grooves 202 may be the same as the width of the heat dissipation groove 201c, or may be larger than the width of the heat dissipation groove 201c. Also, the number of relatively deep heat dissipation grooves 202 may be one, or may be three or more.

[0046] As shown in FIG. 5, in the plurality of heat dissipation ribs 210 that define the plurality of heat dissipation grooves 200, the vertical positions of the lower ends of the two outermost heat dissipation ribs 210a (also referred to as the outermost heat dissipation ribs 210a) located on the outermost side are the same as each other. And the lower end of each outermost heat dissipation rib 210a is located below the lower ends of the other heat dissipation ribs 210. Among the plurality of heat dissipation ribs 210, the vertical positions of the lower ends of the plurality of heat dissipation ribs 210 other than the two outermost heat dissipation ribs 210a are, for example, the same as each other. The lower end of the heat dissipation rib 210 protruding outside the housing 2 can also be said to be the tip of the heat dissipation rib 210.

[0047] In this way, in this example, the vertical positions of the lower ends of the two outermost heat dissipation ribs 210a on both sides are the same as each other, and the lower end of each outermost heat dissipation rib 210a is located below the lower ends of the other heat dissipation ribs 210. Thereby, the lighting device 1 can be placed in a stable state. Therefore, the assembly or installation of the lighting device 1 can be easily performed.

[0048] Note that, among the plurality of heat dissipation ribs 210, the vertical positions of the lower ends of the plurality of heat dissipation ribs 210 other than the two outermost heat dissipation ribs 210a may not be the same as each other. Also, the vertical positions of the lower ends of the two outermost heat dissipation ribs 210a may be different from each other. Further, the lower end of at least one of the two outermost heat dissipation ribs 210a may not be located below the lower end of at least one of the other plurality of heat dissipation ribs 210.

[0049] As shown in FIG. 5, on the inner wall surface 260 of each side wall portion 26 of the housing 2, a groove 265 is provided which is located below the light-transmissive member 5 and extends along the longitudinal direction. The groove 265 extends from the front side to the rear side of the housing 2 along the longitudinal direction. The front opening of the groove 265 constitutes a part of the front opening 21 of the housing 2, and the rear opening of the groove 265 constitutes a part of the rear opening 21 of the housing 2.

[0050] The right end of the left groove 265 (that is, the right opening of the left groove 265) is located to the left of the left end of the substrate 3. The left end of the right groove 265 (that is, the left opening of the right groove 265) is located to the right of the right end of the substrate 3.

[0051] Note that, in the width direction, the position of the right end of the left groove 265 may coincide with the position of the left end of the substrate 3. Also, the right end of the left groove 265 may be located to the right of the left end of the substrate 3. Further, in the width direction, the position of the left end of the right groove 265 may coincide with the position of the right end of the substrate 3. Also, the left end of the right groove 265 may be located to the left of the right end of the substrate 3.

[0052] The left heat dissipation groove 202 has a portion overlapping with the left groove 265 in the vertical direction. For example, the right end of the left heat dissipation groove 202 is located to the left of the right end of the left groove 265 (that is, the right opening of the left groove 265), and the left end of the left heat dissipation groove 202 is located to the right of the left end of the left groove 265.

[0053] The heat dissipation groove 202 on the right has a portion that overlaps with the groove 265 on the right in the vertical direction. For example, the left end of the heat dissipation groove 202 on the right is located to the right of the left end of the groove 265 on the right (i.e., the opening on the left side of the groove 265 on the right), and the right end of the heat dissipation groove 202 on the right is located to the left of the right end of the groove 265 on the right.

[0054] Note that the heat dissipation groove 202 on the left only needs to have a portion that overlaps with the groove 265 on the left in the vertical direction. For example, the left end of the heat dissipation groove 202 on the left may be located to the left of the left end of the groove 265 on the left. Also, the right end of the heat dissipation groove 202 on the left may be located to the right of the right end of the groove 265 on the left.

[0055] Also, the heat dissipation groove 202 on the right only needs to have a portion that overlaps with the groove 265 on the right in the vertical direction. For example, the right end of the heat dissipation groove 202 on the right may be located to the right of the right end of the groove 265 on the right. Also, the left end of the heat dissipation groove 202 on the right may be located to the left of the left end of the groove 265 on the right.

[0056] In the example of Fig. 5, the position of the upper end of the heat dissipation groove 202 on the left in the vertical direction (in other words, the position of the bottom of the heat dissipation groove 202 on the left in the vertical direction) and the position of the upper end of the heat dissipation groove 202 on the right in the vertical direction (in other words, the position of the bottom of the heat dissipation groove 202 on the right in the vertical direction) are the same as each other. And the upper end of each heat dissipation groove 202 is located below the lower surface 36 of the substrate 3 in the vertical direction.

[0057] The position of the upper end of each heat dissipation groove 202 is not limited to this. For example, the upper end of the heat dissipation groove 202 on the left may be located at the same position as the lower surface 36 of the substrate 3 or above the lower surface 36 of the substrate 3 in the vertical direction. Also, the upper end of the heat dissipation groove 202 on the right may be located at the same position as the lower surface 36 of the substrate 3 or above the lower surface 36 of the substrate 3 in the vertical direction. Also, the position of the upper end of the heat dissipation groove 202 on the left in the vertical direction and the position of the upper end of the heat dissipation groove 202 on the right in the vertical direction may be different from each other. For example, the upper end of the heat dissipation groove 202 on the left may be located above the lower surface 36 of the substrate 3 in the vertical direction, and the upper end of the heat dissipation groove 202 on the right may be located at the same position as the lower surface 36 of the substrate 3 in the vertical direction.

[0058] FIG. 8 is a schematic view showing an example of a state in which the upper ends of the heat dissipation grooves 202 are located at the same position as the lower surface 36 of the substrate 3 in the vertical direction. FIG. 9 is a schematic view showing an example of a state in which the upper ends of the heat dissipation grooves 202 are located above the lower surface 36 of the substrate 3 in the vertical direction.

[0059] In the example of FIG. 5, the vertical distance a1 between the upper end of the left heat dissipation groove 202 and the lower end of the left groove 265 is equal to or greater than the thickness t1 of the substrate 3, but the distance a1 is not limited thereto. The distance a1 may be equal to or less than the thickness t1. In the example of FIG. 9 described above, the distance a1 is smaller than the thickness t1.

[0060] The method of fixing the lid portion 6 to the housing 2 is not limited to the above example. The fixing of the lid portion 6 to the housing 2 may be other than screwing. For example, fitting claws may be provided on one of the lid portion 6 and the housing 2, and fitting recesses or fitting holes that fit with the fitting claws may be provided on the other of the lid portion 6 and the housing 2.

[0061] In the lighting device 1 having the above-described configuration, the heat generated by the light-emitting device 4 is transmitted to the light-transmissive member 5 through the substrate 3, the bottom wall portion 25 of the housing 2, and the side wall portion 26 of the housing 2. When the amount of heat transmitted to the light-transmissive member 5 is large, the light-transmissive member 5 may be deformed or the light transmittance of the light-transmissive member 5 may be reduced.

[0062] In this example, the lighting device 1 includes a groove 265 provided on the inner wall surface 260 of the side wall portion 26, located below the light-transmissive member 5, and extending along the longitudinal direction. As a result, the heat transfer path through which the heat generated by the light-emitting device 4 is transmitted to the light-transmissive member 5 through the substrate 3 and the side wall portion 26 becomes narrow around the groove 265. Therefore, it is difficult for heat to be transmitted to the light-transmissive member 5. Further, in this example, since the plurality of heat dissipation grooves 200 include relatively deep heat dissipation grooves 202, the heat dissipation area of the plurality of heat dissipation grooves 200 can be increased, and the heat dissipation effect of the plurality of heat dissipation grooves 200 can be enhanced. As a result, it is difficult for heat to be transmitted to the light-transmissive member 5. Therefore, the possibility that the light-transmissive member 5 is deformed or the light transmittance of the light-transmissive member 5 is reduced is reduced.

[0063] Also, in the example of FIG. 5 and the like, since the heat dissipation groove 202 is located on the outer wall surface 269 side of the side wall portion 26 rather than the substrate 3, even if the upper end of the heat dissipation groove 202 (in other words, the bottom of the heat dissipation groove 202) is arranged upward, it is difficult for the upper end of the heat dissipation groove 202 to reach the substrate 3. Therefore, the depth of the heat dissipation groove 202 can be increased. Thus, the heat dissipation effect of the plurality of heat dissipation grooves 200 can be enhanced. Since the second heat dissipation groove 202 is located on the outer wall surface 269 side of the side wall portion 26 rather than the substrate 3, it can be designed to be deeper than the first heat dissipation groove 201 more easily.

[0064] Also, in the example of FIG. 5 and the like, since the heat dissipation groove 202 has a portion overlapping with the groove 265 of the side wall portion 26 in the vertical direction, without increasing the size of the housing 2 in the width direction, the heat transfer path between the heat dissipation groove 202 and the groove 265 can be narrowed. Thereby, without increasing the size of the housing 2 in the width direction, it is possible to make it difficult for heat to be transmitted to the light-transmissive member 5.

[0065] Also, in the examples of FIGS. 8 and 9, since the upper end of the heat dissipation groove 202 (in other words, the bottom of the heat dissipation groove 202) is located at the same position as the lower surface 36 of the substrate 3 or above the lower surface 36 of the substrate 3 in the vertical direction, the heat transfer path between the heat dissipation groove 202 and the groove 265 becomes narrow. Thereby, it becomes difficult for heat to be transmitted to the light-transmissive member 5.

[0066] Also, in the example of FIG. 9, since the vertical distance a1 between the upper end of the heat dissipation groove 202 and the lower end of the groove 265 is equal to or less than the thickness t1 of the substrate 3, the heat transfer path between the heat dissipation groove 202 and the groove 265 becomes narrow. Thereby, it becomes difficult for heat to be transmitted to the light-transmissive member 5.

[0067] Also, in the example of FIG. 5 and the like, since the heat dissipation groove 201a has a portion overlapping with the plurality of light-emitting devices 4 in the vertical direction, the heat dissipation effect of the plurality of heat dissipation grooves 200 can be enhanced. Thus, it becomes difficult for heat to be transmitted to the light-transmissive member 5.

[0068] Further, in the example of FIG. 5 and the like, since the grooves 265 are provided in each of the pair of side wall portions 26, heat is less likely to be transmitted to the light-transmissive member 5.

[0069] Further, in the example of FIG. 5 and the like, since the widths of the plurality of heat dissipation grooves 200 are not uniform, by providing the heat dissipation groove 201c having a large width in the plurality of heat dissipation grooves 200, a sufficient passage for air can be secured between the heat dissipation ribs 210, and the weight of the housing 2 can be reduced.

[0070] Note that the housing 2 may not include the groove 265 on the left side, may not include the groove 265 on the right side, or may not include both grooves 265.

[0071] Further, the shape of the housing 2 is not limited to the above. For example, one end in the longitudinal direction of the housing 2 may be curved. Also, the basic shape of the housing 2 may be a cube instead of a rectangular parallelepiped that is long in one direction. Further, at least one protrusion necessary for using the lighting device 1 may be provided on the outer surface of the housing 2.

[0072] As described above, the lighting device has been described in detail. However, the above description is illustrative in all aspects, and this disclosure is not limited thereto. Also, the various examples described above can be applied in combination as long as they do not conflict with each other. And an infinite number of examples not illustrated are understood to be assumable without departing from the scope of this disclosure.

[0073] The present disclosure includes the following content.

[0074] In one embodiment, (1) the lighting device includes a housing having an opening at the upper end and being long in one direction, a substrate located on the inner bottom surface of the housing and extending along the longitudinal direction of the housing, a plurality of light-emitting devices mounted on the upper surface of the substrate and arranged along the longitudinal direction, and a light-transmissive member located above the plurality of light-emitting devices and attached to a pair of first side wall portions and second side wall portions along the longitudinal direction of the housing. The housing has a first groove provided on the inner wall surface of the first side wall portion, located below the light-transmissive member, and extending along the longitudinal direction, and a plurality of heat dissipation grooves provided on the outer bottom surface of the housing and extending along the longitudinal direction. The plurality of heat dissipation grooves include a first heat dissipation groove and a second heat dissipation groove deeper than the first heat dissipation groove.

[0075] (2) For the lighting device in (1) above, the second heat dissipation groove is located on the outer wall surface side of the first side wall portion with respect to the substrate.

[0076] (3) For the lighting device in (1) or (2) above, the second heat dissipation groove has a portion overlapping with the first groove in the vertical direction.

[0077] (4) For the lighting device in (3) above, the upper end of the second heat dissipation groove is located at the same position as the lower surface of the substrate or above the lower surface of the substrate in the vertical direction.

[0078] (5) For the lighting device in (4) above, the vertical distance between the upper end of the second heat dissipation groove and the lower end of the first groove is equal to or less than the thickness of the substrate.

[0079] (6) For any one of the lighting devices in (1) to (5) above, the first heat dissipation groove has a portion overlapping with the plurality of light-emitting devices in the vertical direction.

[0080] (7) For any one of the lighting devices in (1) to (6) above, the widths of the plurality of heat dissipation grooves are not uniform.

[0081] (8) The lighting device according to any one of (1) to (7) above, wherein among the plurality of heat dissipation ribs that define the plurality of heat dissipation grooves, the vertical positions of the lower ends of the two outermost heat dissipation ribs are the same as each other, and the lower ends of the two outermost heat dissipation ribs are located lower than the lower ends of the other heat dissipation ribs.

[0082] (9) The lighting device according to any one of (1) to (8) above, wherein the housing is provided on the inner wall surface of the second side wall portion, is located below the light-transmissive member, and has a second groove extending along the longitudinal direction.

[0083] (10) The lighting device according to any one of (1) to (9) above, wherein the plurality of heat dissipation grooves includes a third heat dissipation groove deeper than the first heat dissipation groove.

[0084] (11) The lighting device according to (10) above, wherein the third heat dissipation groove is located on the outer wall surface side of the second side wall portion with respect to the substrate.

[0085] (12) The lighting device according to (11) above, wherein the third heat dissipation groove has a portion overlapping the second groove in the vertical direction.

[0086] (13) The lighting device according to (12) above, wherein the upper end of the third heat dissipation groove is located at the same position as the lower surface of the substrate or above the lower surface of the substrate in the vertical direction.

[0087] (14) The lighting device according to (13) above, wherein the vertical distance between the upper end of the third heat dissipation groove and the lower end of the second groove is equal to or less than the thickness of the substrate.

[0088] (15) The lighting device according to any one of (1) to (14) above, wherein the housing is provided on the inner wall surface of the first side wall portion, protrudes inward, and has a first upper locking portion and a first lower locking portion that sandwich the light-transmissive member in the vertical direction. The first upper locking portion is provided at the upper end portion of the inner wall surface of the first side wall portion, and the tip of the first upper locking portion is located on the outer wall surface side of the first side wall portion with respect to the tip of the first lower locking portion.

[0089] (16) The lighting device according to (15) above, wherein the housing is provided on the inner wall surface of the second side wall portion, protrudes inward, and has a second upper locking portion and a second lower locking portion that sandwich the light-transmissive member in the vertical direction. The second upper locking portion is provided at the upper end portion of the inner wall surface of the second side wall portion, and the tip of the second upper locking portion is located on the outer wall surface side of the second side wall portion rather than the tip of the second lower locking portion.

[0090] (17) The lighting device according to any one of (1) to (16) above, wherein the light emitted by the light-emitting device and emitted from the opening to the outside of the housing through the light-transmissive member is irradiated onto the plant for plant growth.

Explanation of reference numerals

[0091] 1 Lighting device 2 Housing 3 Substrate 4 Light-emitting device 5 Light-transmissive member 26 Side wall portion 35 Upper surface 36 Lower surface 120 Inner bottom surface 125 Outer bottom surface 200, 201, 201a, 201b, 201c, 202 Heat dissipation grooves 260 Inner wall surface 261 Upper locking portion 262 Lower locking portion 265 Groove 269 Outer wall surface a1 Distance t1 Thickness

Claims

1. a housing having an opening at the upper end and being long in one direction, a substrate located on the inner bottom surface of the housing and extending along the longitudinal direction of the housing, a plurality of light emitting devices mounted on the upper surface of the substrate and arranged along the longitudinal direction, a light transmissive member located above the plurality of light emitting devices and attached to a pair of first side wall portions and second side wall portions along the longitudinal direction of the housing and comprising, the housing has a first groove provided on the inner wall surface of the first side wall portion, located below the light transmissive member, and extending along the longitudinal direction, and a plurality of heat dissipation grooves provided on the outer bottom surface of the housing and extending along the longitudinal direction and having, the plurality of heat dissipation grooves include a first heat dissipation groove and a second heat dissipation groove deeper than the first heat dissipation groove, a lighting device.

2. The lighting device according to claim 1, wherein the second heat dissipation groove is located on the outer wall surface side of the first side wall portion with respect to the substrate, a lighting device.

3. The lighting device according to claim 2, wherein the second heat dissipation groove has a portion overlapping the first groove in the vertical direction, a lighting device.

4. The lighting device according to claim 3, wherein the upper end of the second heat dissipation groove is located at the same position as the lower surface of the substrate or above the lower surface of the substrate in the vertical direction, a lighting device.

5. The lighting device according to claim 4, wherein the vertical distance between the upper end of the second heat dissipation groove and the lower end of the first groove is equal to or less than the thickness of the substrate, a lighting device.

6. The lighting device according to any one of claims 1 to 5, wherein the first heat dissipation groove has a portion overlapping the plurality of light emitting devices in the vertical direction, a lighting device.

7. The lighting device according to any one of claims 1 to 5, wherein the widths of the plurality of heat dissipation grooves are not uniform, a lighting device.

8. The lighting device according to any one of claims 1 to 5, wherein among the plurality of heat dissipation ribs defining the plurality of heat dissipation grooves, the vertical positions of the lower ends of the two outermost heat dissipation ribs are the same as each other, and the lower ends of the two outermost heat dissipation ribs are located lower than the lower ends of the other heat dissipation ribs, a lighting device.

9. The lighting device according to any one of claims 1 to 5, wherein the housing has a second groove provided on the inner wall surface of the second side wall portion, located below the light transmissive member, and extending along the longitudinal direction, a lighting device.

10. The lighting device according to any one of claims 1 to 5, wherein the plurality of heat dissipation grooves includes a third heat dissipation groove deeper than the first heat dissipation groove.

11. The lighting device according to claim 10, wherein the third heat dissipation groove is located on the outer wall surface side of the second side wall portion with respect to the substrate.

12. The lighting device according to claim 11, wherein the third heat dissipation groove has a portion overlapping with the second groove in the vertical direction.

13. The lighting device according to claim 12, wherein an upper end of the third heat dissipation groove is located at the same position as a lower surface of the substrate or above the lower surface of the substrate in the vertical direction.

14. The lighting device according to claim 13, wherein a vertical distance between the upper end of the third heat dissipation groove and a lower end of the second groove is equal to or less than a thickness of the substrate.

15. The lighting device according to any one of claims 1 to 5, wherein the housing is provided on an inner wall surface of the first side wall portion, has a first upper locking portion and a first lower locking portion that protrude inward and sandwich the light-transmissive member in the vertical direction, the first upper locking portion is provided at an upper end portion of the inner wall surface of the first side wall portion, and a tip of the first upper locking portion is located on the outer wall surface side of the first side wall portion with respect to a tip of the first lower locking portion.

16. The lighting device according to claim 15, wherein the housing is provided on an inner wall surface of the second side wall portion, has a second upper locking portion and a second lower locking portion that protrude inward and sandwich the light-transmissive member in the vertical direction, the second upper locking portion is provided at an upper end portion of the inner wall surface of the second side wall portion, and a tip of the second upper locking portion is located on the outer wall surface side of the second side wall portion with respect to a tip of the second lower locking portion.

17. The lighting device according to any one of claims 1 to 5, wherein light emitted by the light-emitting device and exiting from the opening to the outside of the housing through the light-transmissive member is irradiated onto the plant for plant growth.

Images